1. The Field of the Invention
The present invention relates to apparatus and methods for the slow release of a medicament, particularly but not exclusively fluoride for the improved treatment and/or prevention of dental caries.
2. The Relevant Technology
Dental caries consist of demineralization of a tooth caused by bacteria. In the early stages of caries a white spot develops on the tooth and if the disease is not halted and reversed, the enamel surface breaks down to form a lesion. This can then lead to decay and eventually, a fractured or pitted tooth. It is well known that development of dental caries may be reduced by means of various factors, such as diet and oral hygiene measures, anti-microbial treatments and the provision of fluoride to the teeth.
Current methods for administering fluoride include the fluoridation of drinking water, the ingestion of fluoride tablets, the incorporation of fluoride into mouth washes, dentifrices and foods, the topical application of fluoride solutions, gels and varnishes, and recently, the incorporation of fluoride in dental materials and special devices. These have a variable effect on caries which is unpredictable on an individual basis and is dependent on patient compliance in following the prescribed regimen.
Evidence supports the concept of frequent applications of relatively low concentrations of fluoride ions for the elimination of caries. A sustained and controlled release delivery system could help to achieve this goal. At least three general approaches have been reported for the application of sustained and controlled slow releasing systems: (1) a sustained release ingested tablet or capsule (Masuhara et al. 1985); (2) incorporation of fluoride into dental cements (McClean & Wilson); and (3) an intra-oral device attached to the teeth (Minth et al. 1983). However, each of these existing technologies has been difficult to use, unpredictable, susceptible to damage, an irritant to surrounding tissue, or unacceptable to the patient.